This inlines some methods and code that was regressing binding
performance. Improves the score of a bindings benchmark by 15%.

Based on contributions by matavenrath@nvidia.com.

Test: bindings_gl_100_objects_allocated_at_initialization
Bug: angleproject:2777
Change-Id: Ied5fdbc67ced862a36c5145fff5ac94f93b40c21
Reviewed-on: https://chromium-review.googlesource.com/1181865Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>